Metal press hydraulic system noise treatment method

　　When the oil is mixed with air, the metal press is easy to form a cavitation phenomenon in its high-pressure zone, and spreads in the form of pressure waves, forming oil oscillations, resulting in cavitation noise in the system.

　　Excessive wear of the internal components of the hydraulic pump, such as the wear and strain of the cylinder block and the valve plate of the plunger pump, the plunger and the plunger hole and other cooperative parts, make the leakage in the hydraulic pump severe, and the flow pulsation will occur when the hydraulic pump outputs high pressure and small flow oil, resulting in higher noise. At this moment, the deflection Angle of the variable mechanism of the pilot system can be appropriately increased to improve the influence of internal leakage on the output flow of the pump. The servo valve spool of the hydraulic pump and the piston controlling the flow rate will also pulsate during the movement due to partial wear and strain, which will cause the output flow and pressure of the hydraulic pump to shake, resulting in greater oscillation and noise at the pump outlet. At this moment, brush plating or replacement of components with severe wear and strain can be carried out.

　　Metal block Press > The valve plate is also one of the important components that can easily cause noise. During operation, due to surface wear or oil mud deposition in the open part of the unloading tank, the unloading tank will be shortened and the unloading position will be changed, resulting in oil trapping phenomenon, which will lead to higher noise. In the normal repair process, the distribution plate repaired by flat grinding will also show the result of short unloading groove, and the metal block press will also cause greater noise if it is not properly lengthened in time. During the installation process, the large unloading groove of the valve plate must be installed in the high-pressure chamber of the pump, and the sharp Angle direction of the metal block press must be relative to the rotation direction of the cylinder block, otherwise it will also bring greater noise to the system.

　　The relief valve of metal press is prone to high-frequency noise, which is mainly caused by the unstable function of the pilot valve, that is, the noise caused by the air oscillation caused by the high-frequency pressure oscillation of the front chamber of the pilot valve. The main reasons are:

　　(1) The oil is mixed with air, which forms a cavitation phenomenon in the front chamber of the pilot valve and causes high-frequency noise. At this point, the air should be drained in time and prevent outside air from entering from the beginning.

　　(2) The needle valve of the metal block press is excessively worn due to frequent opening during use, so that the cone of the needle valve and the valve seat can not be closely closed, resulting in unstable pilot flow, pressure shaking and noise, and should be repaired or replaced in time at this moment.

　　(3) The pressure regulating function of the pilot valve is unstable due to the fatigue and deformation of the spring, which makes the pressure shake and cause noise, and the spring should be replaced at this moment.

　　The noise of the hydraulic cylinder, the oil mixed with air or the air in the hydraulic cylinder is not completely drained, and the gas cavitation phenomenon under the high pressure effect causes greater noise. At this moment, the air must be drained in time. The cylinder head oil seal is too tight or the piston rod is tortuous, and noise will occur during the movement due to other forces. At this point, it is necessary to replace the oil seal or straighten the piston rod in time.